The Collaborative International Dictionary of English v.0.48:

Impeople \Im*peo"ple\, v. t. [imp. & p. p. Impeopled; p. pr. &
   vb. n. Impeopling.] [See Empeople.]
   To people; to give a population to. [Obs.]
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         Thou hast helped to impeople hell.       --Beaumont.
   [1913 Webster]